Friday, November 19, 2010

Mini-Update: LED Dome Lamps

Just another little Mini-Update:

When I was ordering some other parts from JC Whitney, I needed a few more items to get to the free shipping threshold, so I went ahead and ordered a pair of these Ultraflex LED Dome Lamps, in the 2.5"x1.5" size, in order to retrofit them into the dome lamps on the Astrolander conversion.

These are a 24-LED array, but they needed a flat place to mount, so I had to do a little work.

The kit includes a variable-size shunt that fits in place of the original incandescent bulb and provides a 12v/gnd connection. Then I notched the enclosure with a couple of slots.

Then I cut this shelf from a piece of scrap ABS plastic. Excuse the crude work, I was going fast trying to finish before returning to my Daddy duties on a Saturday. The ABS was from an unused portion of a drawer organizer in the recycling bin.

The tabs on the ABS mate to the slots in the housing. Two on one side, one on the other. The ABS is about an 1/8" thick, but is fairly flexible, so easy enough to bend to insert and remove from the slots, which is important since the mounting holes for the dome lamp assembly are behind it, on either side of the original bulb.

The LED matrix then is affixed to the ABS with the supplied double-stick tape (already applied to the back of the PCB). The mating connection is plugged in to the shunt adapter.

In this location it has 1/4" or so of relief from the diffuser lens. Unless you're really looking, you can't tell there's anything different under there.

Until you turn it on. Compare the brightness against the incandescent map lights. These will get converted to LEDs too, as soon as I find an LED kit with an appropriate bulb adapter or have time to make a few from hacked bulbs.

This is a daylight shot, and you can already see the brightness of the LEDs (foreground) versus the incandescent bulb (background). These have made a huge difference in the ease of buckling baby into the car seat after dark. They are NOT a perfect white, they do cast a bit of a blue hue, but for this purpose and the price, I am quite happy. When I do the map lights, I may be a bit more careful about the color temperature as map reading, etc. is hard under bad lighting. I'm also considering red LEDs for the front map lights at least, as an option to help preserve night vision.

(Large pics as always on my web album).